Month: August 2015

Aurora RDS: AWS Released encryption for Aurora Instances. Encryption is not available as of now. Amazon RDS Encryption Links Encrypting Amazon RDS Resources You can encrypt your Amazon RDS instances and snapshots at rest by enabling the encryption option for…

Iworked with CentOS servers from Windows PCs,andIhad the same problem with PuTTY.Asession didn't last more than 1-5 minutes. I tried to play with PuTTY settings (keepalives, etc.) but it didn'thelp at all.

FinallyIhave found the solution formy case.I've recorded TCP dumps both on the client and the server. I've discovered that during25-30seconds before disconnecting there are several retransmissions of TCP segments inthe client's dump (both from the client'sandfrom the server's side) and finally PuTTY sends RST and close the session with that error. In the server'sdumpIdidn't see any segments from the client in this period, even RST. It means that time to time no TCP segments from the client are delivered to the server and this period is about 30-60 seconds. I've recorded the caseseveral times andalways there were retransmissions andfinalRST from PuTTY.Probably somewhere on the route packets were dropped by network equipments.

TomakeaworkaroundI've increased the maximal number of data retransmissions from the default value 5 up to 16. It could prevent PuTTY from disconnection too fast. The variable is 'HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\TcpMaxDataRetransmissions'. I've added thisvariable manually,it wasn'tinitially defined inthe registy of my Windows.It did help!NowIsee that PuTTY hangs from time totime,but it always comes back.